(1) Field of the Invention
The present invention relates to a folding communication terminal and a display control method therefor, and in particular to a technique for controlling illumination of a display of the folding communication terminal, that is visible to the user when the folding communication terminal is in a closed state and that is capable of multicolor displaying.
(2) Description of the Related Art
In recent years mobile communication devices which are used in systems such as PHS (Personal Handyphone System), PDC (Personal Digital Cellular telecommunication system), and CDMA (Code Division Multiple Access) have become common because of decreases in their size and weight, improvement in their communication quality, and reduction of prices of the devices themselves and call charges, and are now a must-have for young people. Recently, folding communication terminals which are fashionable and allow for easy operation are extremely popular, with manufacturers competing against each other to sell folding communication terminals.
Japanese Laid-Open Patent Application H11-74953 discloses a technique regarding a conventional folding communication terminal, which is already well-known. In the technique the folding communication terminal is provided with a sub-display that notifies the user of information about incoming-calls and so on, even when the folding communication apparatus is in a folded state, in addition to being provided with a main display. The sub-display is an auxiliary display for displaying a minimum necessary amount of information to the user when the folding communication device is in a closed state. Generally, a sub-display which has a smaller display area and costs less than the main display is used in order to avoid increasing the size and the price of the terminal. Specifically, a color LCD (Liquid Crystal Display) is used for the main display, and a black and white LCD which can display one row of approximately ten characters is used for the sub-display.
The sub-display displays for example (1) stand-by information showing the present time, the electric field strength and so on during stand-by, (2) when an incoming-call is received, a caller's telephone number, or the caller's name which has been stored beforehand in a telephone directory in correspondence with the caller's telephone number, or information showing that the caller's telephone number is not identified, and (3) when there is new detailed information to be displayed on the main screen, the sub-display displays simplified information showing the type and number of pieces of new detailed information.
By reading the aforementioned information displayed on the sub-display, the user can know the time, who a call is from before answering, and whether there is new detailed information to be checked on the main screen, without opening the folding communication terminal.
In particular, when there is a call, the user can identify the caller while the folding communication apparatus is still closed. This saves trouble for the user who might otherwise answer a call from someone with whom they are on bad terms, a salesperson whose caller ID is unset, or a vicious stalker, resulting in unpleasantness for the user, being made to buy an unwanted product, or being entangled in a vicious crime.
In addition, the user is also saved the trouble of regularly having to open the folding communication terminal to check for detailed information because the user knows whether there is new detailed information or not with the folding communication terminal closed.
As described above, operability of folding communication devices is being improved by display of information on the sub-display, but there is a problem in that the display content is extremely difficult to read because of the small size of the sub-display. Thus there is a demand to further improve the visibility of the information displayed while the folding communication terminal is closed.
Note that another method of letting the user know the identity of a caller when the folding communication terminal is closed is to register telephone numbers with ringer melodies in the telephone directory memory in advance. If there is a ringer melody registered in correspondence with a caller's telephone number when there is an incoming-call, the corresponding ringer melody is played, letting the user know who the call is from. For example, if the user registers a ringer melody “I Just Called to Say I Love You” in correspondence only with his/her girl/boyfriend's telephone number, the user knows straight away that a call is from his/her girl/boyfriend when “I Just Called to Say I love You” is played.
However, ringers cause a disturbance at concerts, meetings and so on, meaning that many users set their folding communication terminals to manner mode so that they are notified of calls by a vibration, and many users ordinarily keep their folding communication terminals set to manner mode to avoid the disturbance of unexpected ringing. This means that the method of identifying callers by ringer-melody is not always effective.